import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
import java.util.concurrent.locks.Condition;

public class WriteLock {

    private Sync sync = new Sync();

    private static class Sync extends AbstractQueuedSynchronizer{

        @Override
        protected boolean tryAcquire(int acquires){
            if (compareAndSetState(0, acquires)){
                setExclusiveOwnerThread(Thread.currentThread());
                return true;
            }
            return false;
        }

        @Override
        protected boolean tryRelease(int arg){
            if (getState() == 0){
                throw new IllegalMonitorStateException();
            }
            setExclusiveOwnerThread(null);
            setState(0);
            return true;
        }

        public Condition newCondition(){
            return new ConditionObject();
        }

        @Override
        protected boolean isHeldExclusively(){
            return getState() == 1;
        }

    }

    public void lock(){
        sync.acquire(1);
    }

    public void lockInterruptibly() throws InterruptedException{
        sync.acquireInterruptibly(1);
    }

    public boolean tryLock(){
        return sync.tryAcquire(1);
    }

    public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
        return sync.tryAcquireNanos(1, unit.toNanos(time));
    }

    public void unlock(){
        sync.release(1);
    }

    public Condition newCondition(){
        return sync.newCondition();
    }





}
